The prior art has heretofore proposed the use of a pre-dosing stage and a pre-dosing device for use in coating moving paper and other web material. Generally, in such prior art arrangements, the overall coating apparatus has a coating applicator chamber which at the exit end thereof (that being the end of the coating applicator chamber where the moving paper web leaves such applicator chamber) is effectively defined by a rolling doctor rod. Such a pre-dosing or pre-applicator device is generally known from the publication "Wochenblatt Fuer Papierfabrikation", No. 17, dated 1970, at pages 777 to 782 and in particular at page 780 thereof shown in FIG. 12a along with related descriptive text on that page. The purpose and function of such pre-dosing device is to cause the coating material of the applicator space to be applied to the moving paper web at a rate greater than that subsequently desired and determined by a secondary or finishing doctor blade. In such prior art arrangements, the exit end of the applicator chamber is provided with an effectively transverse dosing gap of between 0.1 mm. and 0.3 mm However, it has been found that with such prior art arrangements it is difficult to achieve uniform pre-dosing of the coating application in that line-type irregularities appear in the coating application; moreover, for all practical purposes, it is impossible, with such prior art arrangements, to achieve uniform pre-dosing of the coating application when the paper web speed exceeds 800 m/min.
Accordingly, the invention as herein disclosed and described is primarily directed to the solution of the aforestated and other related and attendant problems of the prior art.